Assuming a scenario of a positive consumer externality such as immunization where a negative externality such as noise pollution from the vaccine factory also exists. What will such externalities impact social optimal level as well as marginal social benefit/cost, marginal private benefit/cost curves? Please explain with the help of graphs if possible and suggest the impact of different levels of noise.

When there is no negative externalities, the mechanism to eliminate the deadweight loss caused by the positive consumer externality is to give subsidies to producers. Since there is now a negative externality, will this method still work?